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Alewives Had Measurable Impact on Young Bass

March 26, 2008 - The Feb.12 Op-Ed piece "Maine Needs to Reopen St. Croix to Alewives" by Bill Townsend and Brownie Carson contains inaccuracies and omits certain key considerations.

The claim that alewives should be allowed to reach "historical spawning habitat" in the St. Croix River is debatable. It is not a given that alewives historically ascended the river above Grand Falls. The bottom line is that about half the experts believe that alewives did migrate upriver past Grand Falls, while the remaining half maintain few, if any, were able to pass this formidable falls.

Regarding the demise of the young-of-the-year smallmouth bass in Spednic Lake after intrusion of sea-run alewives, we read "this claim had no scientific evidence to support it." No "evidence," perhaps, but compelling biological data compiled over 15 years by former regional fishery biologist Mike Smith.

Smith wrote a number of peer-reviewed reports that are available from the Fishery Division of the Department of Inland Fisheries & Wildlife in Augusta. Following exclusion of alewives from the lake in 1988, Smith's 1998 report showed that average August densities of young-of-the-year bass from 1986-89 ranged from 1 to 7 per 1000 feet of shoreline. Comparable densities for 1994-97 ranged from 18-125 as young-of-the-year bass exhibited a dramatic increase.

Smith noted "bass reproductive success has steadily increased since alewives were excluded from the lake."

Townsend and Carson note the importance of young alewives as forage for various species, including landlocked salmon. While salmon will eat them, smelt is by far their preferred forage.

As smelt go, so go salmon ... when this forage fish is abundant, salmon grow well, but when they are scarce, the salmon fishery declines.

We are also led to believe that more alewives would be beneficial because more alewives equals more nutrients. This politically correct, but biologically deficient, concept inexplicably ignores these St. Croix watershed attributes:

1) West Grand Lake is one of the top 10 salmon fisheries in Maine.
2) East Grand Lake for many years was loaded with smelt until an illegal introduction of landlocked alewives in 1997 wreaked havoc with the smelt and salmon growth. It is, or perhaps more accurately, was one of Maine's top 10 salmon lakes.
3) Big Lake is one of the state's top 10 smallmouth bass lakes and provides an important salmon (stocked and wild) fishery.
4) The upper St. Croix River is one of the top 10 combination canoeing/ bass fishing trips in Maine.

Now folks, do you believe that a river drainage with such outstanding fisheries is lacking in nutrients? I don't.

The smelt population in Big Lake is already under siege from hordes of landlocked alewives. Allowing up to 120,000 sea-run alewives to pass above Grand Falls would result in many spawning in Big Lake, thereby adding lots of newly hatched sea-run alewives to the hordes of landlocked alewives. This would jeopardize future management by making it more difficult to maintain a decent salmon fishery.

Of further concern, some alewives would swim up Grand Lake Stream to Dam Pool, a mere stone's throw from West Grand. Because LD 1957 carries some high risks with it, I'm convinced it's best to maintain the status quo.

Written by Ron Brokaw, a retired state biologist who oversaw management of the Down East fisheries for more than 25 years.


SOURCE: Central Maine Morning Sentinel

DATE: 03-14-2008


Lakes: Big Lake, East Grand Lake, West Grand Lake
Regions: Lincoln


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